Useless may refer to: Useless (film), a 2007 Chinese documentary by Jia Zhangke Useless (EP), a 2000 EP by Unloco "Useless" (song), a 1997 song by Depeche Mode "Useless", a 2009 song by Cavo from
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfa048dcdda1b4a8ead2c0e65f7405562c0689cb15b7e92de69066ac234643172. Chain 2 (Bitcoin): anchored in block 953924 (2026-06-16T09:52:28Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1d1c1903-c7b7-4d37-9074-09d7359addb3.json and https://artists.proofprofile.net/proofs/artist/1d1c1903-c7b7-4d37-9074-09d7359addb3.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).